Add digits

                    C program to add digits of a number: Here we are using modulus operator(%) to extract individual digits of number and adding them.

#include<stdio.h>
 void main()
{
   int n, sum = 0, remainder;
   printf("Enter an integer\n");
   scanf("%d",&n);
    while( n != 0 )
   {
      remainder = n % 10;
      sum = sum + remainder;
      n = n / 10;
   }

   printf("Sum of digits of entered number = %d\n",sum);

   getch();
}

output :-

Add digits using recursion :-

#include <stdio.h>

#include<conio.h>

int add_digits(int);

 

int main() 

{

  int n, result;

  scanf("%d", &n);

  result = add_digits(n);

  printf("%d\n", result);

  getch();

}

 int add_digits(int n) 

{

  static int sum = 0;

   if (n == 0) 

{

    return 0;

  }

  sum = n%10 + add_digits(n/10);

 return sum;

}